Chitosan Membranes for Direct Methanol Fuel Cell Applications

The purpose of this study is to identify the steps involved in fabricating silica/chitosan composite membranes and their suitability for fuel cell applications. It also intends to identify the physical characteristics of chitosan composite membranes, including their degree of water absorption, proton conductivity, methanol permeability, and functional groups. In this investigation, composite membranes were fabricated using the solution casting method with a chitosan content of 5 g and silica dosage variations of 2% and 4% while stirring at a constant speed for 2 h. According to the findings, the analysis of composite membranes produced chitosan membranes that were successfully modified with silica. The optimum membrane was found to be 4% s-SiO₂ from the Sol-gel method with the composite membrane's optimal condition of 0.234 cm/s proton conductivity, water uptake of 56.21%, and reduced methanol permeability of 0.99 × 10^-7 cm²/s in the first 30 min and 3.31 × 10^-7 in the last 150 min. Maintaining lower water uptake capacity at higher silica content is still a challenge that needs to be addressed. In conclusion, the fabricated membranes showed exceptional results in terms of proton conductivity and methanol permeability.